Sizing device for grinding machines



-NOV. 27 1934. D. GURNEY SIZING DEVICE FOR GRINDING MACHINES Filed Nov.30, 1931 2 Sheets-Sheet 1 INVENTQR NOV, 27, 31934. D GURNEY SIZINGDEVICE FOR GRINDING MACHINES ZSheetSQ-Sheet 2 Filed NOV. 50, 1931INVENTOR ATT RNEY Patented Nov. 27, 1934 UNITED STATES PATENT OFFICESIZING DEVICE FOR GRINDING MACHINES Application November 30, 1931,Serial No. 578,101

6 Claims.

- grinding machines.

An object of the invention is to provide a device of this kind whichwill be sensitive and hence highly accurate in sizing the work inabrading or similar operations.

A further object is to provide a sizing device having electrical controlor other control means for operating certain mechanism on the grindingmachine when the work has been reduced substantially to finished sizeand to operate further mechanism when the work has been ground tofinished size and polished.

A further object is to provide a sizing device having means foradjusting the amount of stock left on the work to be removed duringfinishing grinding.

A further object is to provide a sensitive sizing device, having amechanical electrical multiplying system, which is relatively unaffectedby dirt, water, or rough handling.

A still further object is to provide a sizing device so mounted on themachine with which it is to be used as to be easily swung out ofoperative position.

Further objects and advantages will become more apparent as thedescription proceeds.

' Referring to the accompanying drawings which are made a part hereofand on which similar reference characters indicate similar parts,

Figure 1 is a view in side elevation of the sizing device,

Figure 2, a detail of a connection between a contacting arm on thedevice and the support to which it is attached,

Figure 3, a diagrammatic view of the control circuits and operatingmotors or solenoids controlled thereby, and

Figure 4, an end view looking from the right in Figure 1.

In the drawings numeral 10 indicates a frame or supporting means whichmay be attached in any suitable way to an arm 62 swingably mounted onthe grinding machine. A block 11 is attached to the frame by means offour resilient bars or straps 12 and to the block 11 is attached an arm13 which is bent at its lower end and carries a hard contact element 14which is adapted to engage the interior of the work 15. The block 11 atits upper end has a pin 16 secured in it on the upper end of which pinis a knurled knob 18. A spring 17 is seated within an opening in aportion of the frame 10 and bears against the inner end of the knob 18and tends to hold the block 11 in its uppermost position. In order toswing the feeler arm out of engagement with the work the operatorpresses down on the knob 18 against the tension of a spring 17.

The block 11 has a projection extending into the frame 10 and to thisprojection is attached a magnifying lever 19. The means for attachingthe lever 19 to the block 11 consists of blocks 20 and 21. The block 21is secured to the side of the block 11 and the lever 19 is secured toblock 20. Blocks 20 and 21 are secured together by means of resilientstraps 22 and 23. The rear end of the block 20 is engaged by a screw 24which is secured in the frame 10 and locked in position by a nut 25. Aspring 26 engages the end of the block 20 in opposition to the screw 24.A'bearing pin 27 is secured on the block 20 to provide hard engagingsurface with the end of the screw 24. The free end of the lever 19carries a disk 28 which is positioned in a liquid filled cup 29 which issecured to the frame 10 by screw 30. This arrangement provides means fordampening rapid vibrations of the lever. The .lever 19 also carries adrum or spool 31 of bakelite or other insulating material, the surfaceof which is always in contact with the bent ends of resilient fingers 32and 33. Finger 32 carries a contact point 34 and finger 33 a contactpoint 35 which points are positioned adjacent and engageable withcontact points 36 and 3'7 on arms 38 and 39 respectively. The finger 33and arm 39 are secured to block 40 mounted on an arm 51 pivoted at 52and urged in a clockwise direction by a spring 42. The block 40 isengageable by a screw 41 by means of which it may be adjusted verticallyand locked by means of a nut 43. Bar 38, finger 32, bar 39 and finger 33are connected respectively by means of wires 44, 45, and 46. The wire 45connects to finger 32 and bar 39 through a resilient strap or bar 64,the resiliency of which permits the necessary adjustment of block 40.The arm 62 is attached to or made integral with sleeve 53, which isrotatably carried on a post 54 and urged upward by spring 48, through athrust bearing 47. This sleeve 53 is positioned vertically by the lowerface of a sleeve 60, which is adjustable on the post through a knurlednut 61. By means of this construction, the device may be swung around tothe dotted line position shown in Fig. 4 and may be adjusted verticallyby means of nut 61 to change the finished size of the piece beingground.

In Figure 3 is shown diagrammatically the operation of the device andparticularly the circuits and the means operated by the circuits asshown. In operation when the work has been reduced .work being groundmay move upward allowing the lever 19 to swing clockwise. The firstresult of this upward movement will be to bring contacts 35.

and 37 together. This will close circuit from battery 57 through wires46 and 45 and motors or solenoids 55 and 56. These solenoids may controloperation of certain mechanism on the grinding machine such as means forstopping feeding of the grinding wheel toward the work and slowing downoscillation or rotation of the work. When the work has been reduced tofinished size contacts 34 and 36 will be brought together to closecircuit from battery 57 through wires 44 and 45 and energize solenoids58 and 59. These solenoids may control means for stopping furthergrinding operation and withdraw the grinding wheel from the work orperform any other operations which are necessary at the conclusion ofgrinding a piece of work. By means of screw 41 the timing betweenclosing of contacts 35 and 37 and contacts 34 and .36 may be regulatedso as to leave a predetermined amount of stock on the work to be removedduring finished grinding.

A gauge 49 having a dial to indicate the size of the work may be mountedon the frame in any suitable way.

Mechanical and electrical elements are mounted independently so thatthere are no electrical connections on the multiplying arm 19 or othermoving parts. The arm is mounted in such a way with respect to thecontacts that a continuous movement of said arm in one direction causesfirst one circuit to be closed, then after a short interval, which maybe varied by the operator, the other circuit is completed.

It is essential that my device be dust and dirt proof either byenclosing all working parts or by making use of a type of constructionwhich would not be affected by dust or dirt. Such a construction isprovided in spring supports 12 and spring hinges 22 and 23; also, thereis no wear in these parts which would affect the accuracy of the device.The electrical elements are sufficiently enclosed to guard against dustand dirt.

It will be obvious to those skilled in the art that various changes maybe made in my device without departing from the spirit of the inventionand therefore I do not limit myself to what is shown in the drawings anddescribed in' the specification, but only as indicated by the appendedclaims.

Having thus fully described my said invention, what I claim as new anddesire to secure by Letters Patent, is:

1. In a grinding machine, a sizing device compris'ng work engagingmeans, a multiplying lever operable by said work engaging means, a pairof contacts biased to closed position but normally held open by saidlever, said contacts being in circuit with means for controllingoperation of some mechanisms on the machine, a second'pair of contactsnormally biased to open position and in circuit with electricallyoperated mechanism on the machine, movement of said lever in response toreduction in work causing said first contacts to close, and furthermovement closing said second contacts.

2. In a machine tool, a work sizing device comprising work engagingmeans, a multiplying lever operated by said work engaging means, a pairof contacts biased toward closed position during operation of themachine tool on which the sizing device is mounted, a pair of normallyopen contacts, electric circuits controlled by said contacts, meansoperated by said lever when in normal position for holding said firstnamed contacts in open position, and means responsive to movement ofsaid lever for closing said normally opened circuit.

3. A sizing device comprising work engaging means, a support for saidmeans, a multiplying lever pivotally mounted on the said support, a pairof electrical contacts, one of which is biased to closed position andthe other of which is biased to open position, and means operable topermit one of said contacts to move to closed position and to force theother contact to closed position when the work engaging means has movedto a position representing a predetermined size of the work.

4. A sizing device comprising work engaging means, a support for thework engaging means, a multiplying lever resiliently mounted on saidsupport, movement of the work engaging means in one direction beingmultiplied by said lever, but having no effect on said multiplying leverwhen moved in the other direction.

5. A sizing device comprising work engaging means, a support for thework engaging means, a lever mounted on said support, electricalcontacts mounted independently of said lever but adapted to be actuatedthereby, means whereby movement of the work engaging means in onedirection is multiplied to actuate said contacts, and means to rendersaid multiplying means inoperative when said work engaging means movesin' the cppositeniirection.

6. A sizing device comprising work engaging means, a support for thework engaging means, a multiplying lever pivotally mounted on saidsupport, a plurality of electric contacts adapted to be made and broken.by said multiplying lever, pivoting of said multiplying lever beingpermitted only in one direction of movement of the said work engagingmeans.

DANIEL GURNEY.

